Singular kernels, multiscale decomposition of microstructure, and dislocation models

We consider a model for dislocations in crystals introduced by Koslowski, Cuiti\~no and Ortiz, which includes elastic interactions via a singular kernel behaving as the $H^{1/2}$ norm of the slip. We obtain a sharp-interface limit of the model within the framework of $\Gamma$-convergence. From an analytical point of view, our functional is a vector-valued generalization of the one studied by Alberti, Bouchitt\'e and Seppecher to which their rearrangement argument no longer applies. Instead we show that the microstructure must be approximately one-dimensional on most length scales and exploit this property to derive a sharp lower bound

Tightness for a stochastic Allen--Cahn equation

We study an Allen-Cahn equation perturbed by a multiplicative stochastic noise which is white in time and correlated in space. Formally this equation approximates a stochastically forced mean curvature flow. We derive uniform energy bounds and prove tightness of of solutions in the sharp interface limit, and show convergence to phase-indicator functions.Comment: 27 pages, final Version to appear in "Stochastic Partial Differential Equations: Analysis and Computations". In Version 4, Proposition 6.3 is new. It replaces and simplifies the old propositions 6.4-6.

Cloud resource orchestration in the multi-cloud landscape: a systematic review of existing frameworks

The number of both service providers operating in the cloud market and customers consuming cloud-based services is constantly increasing, proving that the cloud computing paradigm has successfully delivered its potential. Nevertheless, the unceasing growth of the cloud market is posing hard challenges on its participants. On the provider side, the capability of orchestrating resources in order to maximise profits without failing customers’ expectations is a matter of concern. On the customer side, the efficient resource selection from a plethora of similar services advertised by a multitude of providers is an open question. In such a multi-cloud landscape, several research initiatives advocate the employment of software frameworks (namely, cloud resource orchestration frameworks - CROFs) capable of orchestrating the heterogeneous resources offered by a multitude of cloud providers in a way that best suits the customer’s need. The objective of this paper is to provide the reader with a systematic review and comparison of the most relevant CROFs found in the literature, as well as to highlight the multi-cloud computing open issues that need to be addressed by the research community in the near future

The effect of body mass index on chest trauma severity and prognosis

AIM: Patients with thoracic trauma constitute one third of all the trauma cases, in west Sicily were recorded 941 thoracic trauma during the period between 2006 and 2009. Sicily is one of the Italian regions with the highest rate of obesity: some studies have demonstrated that obesity is an independent risk factor for mortality in high energy blunt traumas. MATERIAL OF STUDY: This study was conducted with trauma patients older than 20 years old who presented to our Department during the last five years. We only included thoracic injuries and politrauma with a thoracic involvement and a BMI > 25- Patients were divided into two groups: HET and LET patients. RESULTS: Thoracic trauma was more common in patients with a BMI > 25 than in normo-weight and clinic admission rate, length of hospital stay and ISS score increased in proportion with the increase of BMI. Both HET (high energy trauma) and LET (low energy trauma) revealed that overweight, obese and morbidly obese patients had greater admissions and length of hospital stay. DISCUSSION: The overweight and obese population has increased substantially over the last two decades and 61,5% of the Sicilian population is above normal weight. A large body mass with excess adiposity may contribute to HET injuries in several ways. Obesity has a number of comorbidities that reduce chances of recovery in overweight and obese patients experienced thoracic trauma both HET and LET. CONCLUSION: Obesity increases morbidity independently of injury severity in thoracic trauma patients. As BMI increased, length of hospital stay increased and prognosis deteriorates

Application, validation and comparison in different geographical contexts of an integrated model for the design of ecological networks

The issue of the fragmentation of natural habitats is increasingly at the core of the scientific debate, yet it is not taken into account in planning tools, with particular reference to the dynamism and complexity of landscapes. As it has been recognised at a European level, in order to enable different species to remain in good functional status, a network of green infrastructures is required. The concept of “ecological island” is no longer sufficient to adequately protect the fauna and the ecosystem it lives in. As a consequence, ecological islands must turn into ecological networks. The Ecological connectivity refers to the way habitats are physically connected to each other and how easy it is for species to move in. Good ecological connectivity is fundamental to the effective conservation of biodiversity considering that most species and ecological functions provided by ecosystems (ecosystem services) require a much wider space than that available within the boundaries of a single protected area. The main objective of this paper is to critically compare the application of a model for the design of ecological networks to two very different environmental contexts. This model was first tested in a Mediterranean area (the Province of Reggio Calabria) in 2008; the goal was to integrate the traditional (physiographic and functional) approaches into the design of ecological networks by taking into account biological and orographic elements as well as the anthropic structure of the territory. In 2011, within the ECONNECT European project, the model was applied to the pilot region of South-Western Alps (including the French region of Provence-Alpes - Côte d’Azur and the Italian regions Piedmont and Liguria), which is one of the richest transnational districts in Europe in terms of biodiversity. In such a region, the issue of multidisciplinary ecological connectivity was tackled in order to provide a series of proposals aiming at the development of the ecological potential of the area. The two applications allowed to further investigate the strengths and weaknesses of the implemented model by integrating its validation with information on faunal presence, which obviated one of the major limitations occurred in the first application

Branching Structures in Elastic Shape Optimization

Fine scale elastic structures are widespread in nature, for instances in plants or bones, whenever stiffness and low weight are required. These patterns frequently refine towards a Dirichlet boundary to ensure an effective load transfer. The paper discusses the optimization of such supporting structures in a specific class of domain patterns in 2D, which composes of periodic and branching period transitions on subdomain facets. These investigations can be considered as a case study to display examples of optimal branching domain patterns. In explicit, a rectangular domain is decomposed into rectangular subdomains, which share facets with neighbouring subdomains or with facets which split on one side into equally sized facets of two different subdomains. On each subdomain one considers an elastic material phase with stiff elasticity coefficients and an approximate void phase with orders of magnitude softer material. For given load on the outer domain boundary, which is distributed on a prescribed fine scale pattern representing the contact area of the shape, the interior elastic phase is optimized with respect to the compliance cost. The elastic stress is supposed to be continuous on the domain and a stress based finite volume discretization is used for the optimization. If in one direction equally sized subdomains with equal adjacent subdomain topology line up, these subdomains are consider as equal copies including the enforced boundary conditions for the stress and form a locally periodic substructure. An alternating descent algorithm is employed for a discrete characteristic function describing the stiff elastic subset on the subdomains and the solution of the elastic state equation. Numerical experiments are shown for compression and shear load on the boundary of a quadratic domain.Comment: 13 pages, 6 figure

Safety performance assessment of food industry facilities using a fuzzy approach

The latest EU policies focus on the issue of food safety with a view to assuring adequate and standard quality levels for the food produced and/or consumed within the EC. To that purpose, the environment where agricultural products are manufactured and processed plays a crucial role in achieving food hygiene. As a consequence, it is of the utmost importance to adopt proper building solutions which meet health and hygiene requirements and to use suitable tools to measure the levels achieved. Similarly, it is necessary to verify and evaluate the level of safety and welfare of the workers in their working environment. The safety of the workers has not only an ethical and social value but also an economic implication, since possible accidents or environmental stressors are the major causes of the lower efficiency and productivity of workers. However, the technical solutions adopted in the manufacturing facilities in order to achieve adequate levels of safety and welfare of the workers are not always consistent with the solutions aimed at achieving adequate levels of food hygiene, even if both of them comply with sectoral rules which are often unconnected with each other. Therefore, it is fundamental to design suitable models of analysis that allow assessing buildings as a whole, taking into account both health and hygiene safety as well as the safety and welfare of workers. Hence, this paper proposes an evaluation model that, based on an established study protocol and on the application of a fuzzy logic procedure, allows evaluating the global safety level of a building. The proposed model allows to obtain a synthetic and global value of the building performance in terms of food hygiene and safety and welfare of the workers as well as to highlight possible weaknesses. Though the model may be applied in either the design or the operational phase of a building, this paper focuses on its application to certain buildings already operational in a specific productive context

Frontal brain asymmetries as effective parameters to assess the quality of audiovisual stimuli perception in adult and young cochlear implant users

How is music perceived by cochlear implant (CI) users? This question arises as "the next step" given the impressive performance obtained by these patients in language perception. Furthermore, how can music perception be evaluated beyond self-report rating, in order to obtain measurable data? To address this question, estimation of the frontal electroencephalographic (EEG) alpha activity imbalance, acquired through a 19-channel EEG cap, appears to be a suitable instrument to measure the approach/withdrawal (AW index) reaction to external stimuli. Specifically, a greater value of AW indicates an increased propensity to stimulus approach, and vice versa a lower one a tendency to withdraw from the stimulus. Additionally, due to prelingually and postlingually deafened pathology acquisition, children and adults, respectively, would probably differ in music perception. The aim of the present study was to investigate children and adult CI users, in unilateral (UCI) and bilateral (BCI) implantation conditions, during three experimental situations of music exposure (normal, distorted and mute). Additionally, a study of functional connectivity patterns within cerebral networks was performed to investigate functioning patterns in different experimental populations. As a general result, congruency among patterns between BCI patients and control (CTRL) subjects was seen, characterised by lowest values for the distorted condition (vs. normal and mute conditions) in the AW index and in the connectivity analysis. Additionally, the normal and distorted conditions were significantly different in CI and CTRL adults, and in CTRL children, but not in CI children. These results suggest a higher capacity of discrimination and approach motivation towards normal music in CTRL and BCI subjects, but not for UCI patients. Therefore, for perception of music CTRL and BCI participants appear more similar than UCI subjects, as estimated by measurable and not self-reported parameters

Good news or bad news, which do you want first? The importance of the sequence and organization of Information for financial decision-making: a neuro-electrical imaging study

Investment decisions are largely based on the information investors received from the target firm. Thaler introduced the hedonic editing framework, in which suggests that integration/segregation of information influence individual's perceived value. Meanwhile, when evaluating the evidence and information in a sequence, order effect and biases have been found to have an impact in various areas. In this research, the influence of the Organization of Information (Integration vs. Segregation) and the Sequence of Information (Negative-Positive order vs. Positive-Negative order) on individual's investment decision-making both at the behavioral level (decision) and neurometrix level (measured by an individual's emotion and Approach Withdraw tendency) was assessed for the three groups of information: a piece of Big Positive Information and a piece of Small Negative Information, a piece of Big Negative Information and a piece of Small Positive Information, and a piece of Small Negative information. The behavioral results, which are an individual's final investment decision, were consistent for all three scenarios. In general, individuals will invest more/retire less when receiving two pieces of information in a Negative-Positive order. However, the neurometric results (Emotional Index, Approach Withdraw Index and results from LORETA) show differences among information groups. An effect of the Sequence of Information and the Organization of Information was found for the different scenarios. The results suggest that in the scenarios that involve large-scale information, the organization of information (Integration vs. Segregation) influences the emotion and Approach Withdraw tendency. The results of this investigation should provide insight for effective communication of information, especially when large-scale information is involved

Use of biomimicry model for the design of perforated composite plates

There are many practical reasons for making perforations in composites, which include reducing weight and for joining components. Nature often produces strong materials that have multiple perforations allowing organisms to survive in tough environments, biomimicry seeks to utilise these features for artificial solutions. The project proposes to investigate natural structures then using the information gained, to suggest methods by which we could design/make more efficient openings in composite structures. For example, to increase window size in aircraft structures without compromising strength or aerodynamics. Holes are usually made by machining however this project proposes a to use tree knots holes as a model to mould holes in composites. The project will validate its predictions through experimentation. Three types of sample plates were manufactured using resin infusion under flexible tooling (RIFT) and unidirectional fibres. Test samples using both a moulded and drilled hole are compared against each other and that of a control sample without a hole to investigate if tensile improvements have been made. Digital image correlation (DIC) analysis shows a difference in the failure mode of each. The project was limited due to time and resources, so could be usefully repeated with a larger test sample size and different hole sizes. The results show that the moulded holes had a lower tensile strength but a higher tensile modulus than the drilled sample. The location of tow and stitching in the top layer did not appear to affect the results. However, the failure mode of the moulded samples was less catastrophic, showing a more gradual deterioration, which would prove advantageous in real-world scenarios, where products are monitored regularly. This process could be useful as it is reusable and saves on additional machining time and costs. Furthermore, there is no wasted material or risk of delamination and dust when installing components